Ventricular function assisting devices and methods of use thereof

ABSTRACT

The present invention provides devices and methods for assisting in the ventricular function of a treated heart, and tools for delivering and attaching elements of said devices to the wall of the heart. In general the devices of the invention are designed to assist in the ventricular function of the heart by utilizing elastic, and/or magnetic, elements designed to apply radially and/or tangentially directed forces over the wall of the heart, and/or alter the pressure conditions inside ventricle(s) of the heart. Embodiments of the invention may utilize restrictive elements which may optionally be attached over the heart during the implantation procedure, or at a later time, by changing the mode of operation of an implanted device of the invention.

FIELD OF THE INVENTION

The present invention relates to methods and devices for improvingventricular function of the heart. More particularly, the inventionrelates to means for treating systolic and/or diastolic heartdysfunctions.

BACKGROUND OF THE INVENTION

Heart failure (HF) is a complex clinical syndrome that can result fromany structural or functional cardiac disorder that impairs the abilityof the ventricle to fill with or eject blood. The cardinalmanifestations of HF are dyspnea and fatigue, which may limit exercisetolerance, and fluid retention, which may lead to pulmonary congestionand peripheral edema. Heart failure is most commonly associated withimpaired left ventricle (LV) systolic function.

The term diastolic heart failure (DHF) generally refers to the clinicalsyndrome of heart failure associated with preserved left ventricularejection fraction, in the absence of major valvular disease.

Primary diastolic dysfunction is typically observed in patients withhypertension and hypertrophic or restrictive cardiomyopathy, but canalso occur in a variety of other clinical disorders and has aparticularly high prevalence in the elderly population. Aging isassociated with ‘physiologic’ diastolic dysfunction due to the increasein LV muscle mass and changes in passive elastic properties of themyocardium, hence, the concern of an increase in the incidence ofdiastolic dysfunction as the aging of the western world populationprogresses.

There is thus a need for, and it would be highly advantageous to have anin-vivo method and device for improving diastolic function of the heart,while minimally disturbing systolic function of the heart. Moreover,there is a need for such a method and device which is biocompatible andis specially configured for compact and long-term reliable use inhumans.

Various in-vivo methods and devices for improving diastolic function ofthe heart are described in International patent applications Nos.PCT/IL02/00547 (WO 03/007778), PCT/IL05/01014 (WO 06/033107),PCT/IL04/00986 (WO 05/041745), and PCT/IL04/00072 (WO 04/066805), of thesame assignee hereof, the descriptions of which is incorporated hereinby reference. The aforementioned international patent applicationsdescribe elastic means used for improving diastolic function of theright or left ventricle of the heart by pushing and/or pulling, an innerand/or outer wall region of the ventricle during the cardiac cycle whileminimally disturbing the heart function. The present invention providesmodifications, improvements, and new methods and devices, for improvingthe diastolic function of the heart.

SUMMARY OF INVENTION

The present invention provides devices and methods for assisting in theventricular function of a treated heart, and tools for delivering andattaching elements of said devices to the wall of the heart. In generalthe devices of the invention are designed to assist in the ventricularfunction of the heart by utilizing elastic, and/or magnetic, elementsdesigned to apply radially and/or tangentially directed forces over thewall of the heart, and/or alter the pressure conditions insideventricle(s) of the heart.

Embodiments of the invention further utilize restrictive elements whichmay optionally be attached over the heart during the implantationprocedure, or at a later time, by changing the mode of operation of animplanted device of the invention.

In one aspect the present invention is directed to an apparatus capableof selectively assisting diastolic dysfunctions and/or systolicdysfunctions by means of elastic or magnetic elements attached to thewall of the heart and configured to apply radially and/or tangentiallydirected forces thereover. Said apparatus further comprises restrictiveelements adapted to encircle a perimeter (circumference) of the heartand capable of being changed between an engaging state and anon-engaging state, where in said engaging state they restrict heartexpansions during the diastolic phase and in said non-engaging state thediastolic phase is not affected by them.

According to one preferred embodiment of the invention the ventricularfunction assisting apparatus comprises anchoring means capable of beingattached to the wall of the heart, elastic elements capable of beingattached to said anchoring means, at least two restrictive elementsadapted to encircle a perimeter of the heart, said restrictive elementscapable of being changed between a engaging state and a non-engagingstate over the heart, and elongated flexible elements capable of beingattached between said restrictive elements via their extremities whilebeing movably engaged in said anchoring means along portions of theirlengths, wherein said ventricular function assisting device is capableof being selectively changed between two modes of operation by changingthe state of said restrictive means between their non-engaging andengaging states over the heart.

The ventricular function assisting device of the invention is preferablyattached over the heart by placing at least two restrictive elementsmore or less horizontally around the heart, attaching the anchoringmeans to wall region(s) of the heart located between the restrictiveelements, attaching the elastic elements to said anchoring means suchthat they can be elastically deformed and store potential energy in themduring the systolic phase and release said stored energy during thediastolic phase, thereby applying radially outward and tangentiallydirected forces over said wall regions, and attaching the extremities ofsaid elongated flexible elements between said restrictive elements suchthat at least some of them are movably engaged in said anchoring means.

The elastic elements are generally made in a “v” like shape havingtorsion loop(s) at its apex and two arms attached by one of their endsto said torsion loops, where each of said side arms comprisingattachment components at their other end. Preferably, the elasticelements are made from an elastic wire coiled into a “V” like shape suchthat torsion loop(s) are formed at its apex with two side arms, whereinthe end portions of said side arms are curved to form the attachmentcomponents. According to one specific embodiment the attachmentcomponents are made in a “G”-like shape. In an alternative embodimentthe attachment components are made in a “U”-like shape.

The anchoring means are preferably made from a turned wire having abottom and top portions, wherein said bottom portion is formed in ahelical shape adapted to be screwed into a soft tissue and its topportion comprises one or more retaining parts configured to receive theattachment components provided in the elastic elements, wherein some, orall, of the retaining parts are further adapted to movably hold aportion of the elongated flexible elements. In a preferred embodiment ofthe invention the retaining parts are made from a curved wire configuredto receive and hold the attachment components of the elastic elementswhile allowing non-interlocking passage of the elongated flexibleelements through it. Most preferably, the retaining part is formed in ashape of a vertical ring being in a plane substantially vertical to theplane of the helical turns of the bottom portion of the anchoring means.The top portion of the anchoring means may be implemented by a flangedrod having circumferential gaps formed between its flanges used asretaining parts suitable to receive and hold the attachment componentsof the elastic elements. The top portions of the anchoring means mayfurther comprise a dome-like cover for preventing tissue injuries.

The restrictive elements are preferably made from a rigid, orsemi-rigid, circular stripe having a fastening mechanisms capable ofchanging its circumference from a non-engaging state into it engagingstate by reducing its circumference. The fastening mechanism may beimplemented by a fastening screw (e.g., as a gear clamp). Alternatively,the fastening mechanism may be implemented by a spring and a removablesupport bar attached over a gap formed in the restrictive elementconfigured such that its circumference may be reduced by removing saidremovable support bar.

According to one embodiment the restrictive elements have a wavyconfiguration or implemented by tension springs. Advantageously, theflexible elongated elements may attached to the restrictive elements bymeans pulling, or pushing, springs.

In another specific embodiment the flexible elongated elements areattached at one end to a restrictive element while their other end isare attached together by a connecting component near the apex of theheart.

Advantageously, the elastic elements are attached to anchoring meansplaced over the left ventricle of the heart, such that when therestrictive elements of the ventricular function assisting device are intheir non-engaging state the apparatus substantially assists indiastolic heart dysfunction, and whenever said restrictive elements arechanged into their engaging state the apparatus substantially assists inboth diastolic and systolic heart dysfunctions.

In another aspect the present invention is directed to a kit comprisingthe elements of ventricular function assisting device of the inventionand tools capable of delivering and attaching the anchoring means to theheart, and tools capable of delivering and attaching the elasticelements to said anchoring means, wherein said tools are capable ofdelivering and attaching said elements and means via a minimallyinvasive procedure.

According to one embodiment the kit comprises fastening means capable ofholding the top portion of the anchoring means, and a screwing toolcomprising: a proximal handle having a rotatable wheel disposed in its;a hollow shaft attached to said handle, said hollow shaft comprises arotatable rod mechanically linked to said rotatable wheel; a hinged headattached at the distal end of said hollow shaft in which there is arotatable holder capable of receiving and holding said fastening meansin it, wherein said rotatable rod and said rotatable holder aremechanically linked such rotations of said wheel are delivered therebyto said rotatable holder. The hinged head may further comprise foldablelocator capable of indicating the distance between adjacent anchoringmeans place on the wall of the heart.

Additionally or alternatively, the kit may comprise a delivery toolhaving an elongated stack capable of holding a plurality of anchoringmeans, said elongated stack comprising a pushing spring adapted toadvance the anchoring means distally toward a distal opening whereinthere is a screwing head mechanically linked to an electrical motor andcapable of holding the distal-most anchoring means in said stack andmove it out of said stack via said distal opening. Advantageously, thedelivery tool may further comprise optical guiding means mounted onopposing sides in a distal section thereof which are adapted to emit alight beam capable of designating a new location for placing a newanchoring means.

The kit may further comprise a delivery tool suitable for delivering andattaching the elastic elements, comprising a proximal handle having aslider element movably placed therein and capable of being moved betweena proximal and distal states, a slidable hollow shaft comprisingmechanically linked to said slider element, and a an elongated rodfixedly attached to said proximal handle and passing inside said handleand said slidable hollow shaft, wherein said elongated rod comprises aretaining part adapted to receive and hold the torsion loop(s) of anelastic element when said slider element in its proximal state, suchthat the arms of said elastic elements are capable of being folded intosaid slidable hollow shaft by changing the sate of said slider elementinto its distal state.

In another aspect the present invention is directed to a ventricularfunction assisting device utilizing a plunger mechanism designed toincrease the volume of the left ventricle of the heart during diastolicphase and reduce its volume during the systolic phase.

According to one preferred embodiment the ventricular function assistingdevice comprises a cylindrical housing having a front section having afront opening capable of being sealably attached to a first openingformed in a ventricle of the heart, and a rear section to which there isattached a conduit capable of communicating between said rear sectionand said ventricle via a second opening formed therein to which saidconduit is capable of being sealably attached, wherein each of saidsections comprises a slidable plunger movably disposed thereinside, saidplungers are mechanically linked by a connecting rod, and wherein thecross-sectional area of the plunger in the rear section is greater thanthe cross-sectional area of the plunger in the front section, andwherein said plungers are mechanically linked to an elastic element(e.g., spring) mounted inside said ventricular function assisting deviceand adapted to push, or pull said plungers thereinside.

According to another preferred embodiment the ventricular functionassisting device comprises a cylindrical housing a slidable plungerslibably disposed thereinside, said slidable plunger is made from amagnetic or ferromagnetic material, a front and rear coils wound on, orin, the wall of said cylindrical hosing, and a front opening, orpassage, capable of being attached to an opening formed in a ventricleof the heart and communicating between said cylindrical housing and saidventricle, wherein said coils are capable of being electricallyconnected to a controllable current source configured to activate saidcoils, or one of them, to apply magnetic forces for sliding saidslidable plunger rearwardly during the diastole, and to apply magneticforces for sliding said slidable plunger forwardly during the systole.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example in theaccompanying drawings, in which similar references consistently indicatesimilar elements and in which:

FIGS. 1A to 1X schematically illustrate various embodiments ofventricular function assisting devices configured for treating systolicand diastolic dysfunctions and tools suitable for attaching the same tothe heart in a minimally invasive procedure, wherein FIGS. 1A and 1Bshow a configuration of anchoring means and elastic elements havingG-shaped attachments suitable for use in the ventricular functionassisting device, FIGS. 1C to 1F show embodiments of anchoring meanshaving dual-level anchoring sites in their head sections and elasticelements having C-shaped attachments, FIG. 1G shows a perspective viewof a tool for guiding in the positioning of the attachment means, FIG.1H shows a perspective view of the attachment means used in FIG. 1B,FIGS. 1I to 1N show various views and exemplify the use of a tool forattaching the attachment means of the invention to the wall of theheart, FIGS. 1O to 1Q show another embodiment of a tool for attachingthe attachment means to the wall of the heart in which the attachmentmeans are maintained in an internal stack, FIGS. 1R to 1T shows a toolfor delivering and attaching the elastic elements, FIG. 1U shows aperspective view of the ventricular function assisting device of theinvention having two operation modes, FIG. 1V shows the ventricularfunction assisting device shown in FIG. 1U when mounted on a heart, andFIGS. 1W and 1X illustrate an exemplary implementation of a fasteningmechanism (in an open and closed states, respectively) suitable forfastening the ventricular function assisting device over the heart;

FIGS. 2A and 2B schematically illustrate a ventricular functionassisting device which employs elastic restrictive elements;

FIGS. 3A and 3B schematically illustrate ventricular function assistingdevices for treating systolic and diastolic dysfunctions which employ anintermediate restrictive element;

FIGS. 4A to 4C schematically illustrate an implementation of theventricular function assisting device which is configured to enclose theapex of the heart, wherein FIG. 4A is a perspective view, FIG. 4Bschematically illustrates an exemplary fastening mechanism, and FIG. 4Cis a side view;

FIGS. 5A and 5B schematically illustrate a device for treating systolicand diastolic dysfunctions which is based on a magnetic/electromagneticmechanism;

FIGS. 6A and 6B schematically illustrate the structure and operation ofa ventricular function assisting device of the invention based on anplunger mechanism;

FIGS. 7A and 7B respectively show a perspective view and a sectionalview of specific implementations of the ventricular function assistingdevice illustrated in FIGS. 6A and 6B.

FIGS. 8A to 8E show sectional views of various implementations ofventricular function assisting devices of the invention based on plungermechanisms, wherein FIG. 8A shows an embodiment employing an anteriorspring, FIG. 8B shows an embodiment employing a posterior spring, FIG.8C exemplifies attachment of an embodiment employing a posterior springto the heart, FIG. 8D shows an embodiment employing a posterior springplaced in an isolating enclosure, and FIG. 8E exemplifies attachment ofan embodiment employing an anterior spring to the heart;

FIGS. 9A and 9B schematically illustrate a ventricular functionassisting device employing an electromagnetically driven plunger; and

FIGS. 10A and 10B schematically illustrate a method and apparatus forinserting treatment devices into the heart and for mounting the same onits inner wall.

It should be noted that the embodiments exemplified in the Figs. are notintended to be in scale and are in diagram form to facilitate ease ofunderstanding and description.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention provides methods and devices for treating systolicand/or diastolic heart dysfunctions and delivery tools suitable fordelivering and attaching elements to the wall of the heart in aminimally invasive procedure. In general, devices of the presentinvention are designed to assist the operation of the heart by aiding involume enlargement of the left ventricle and by reducing the pressuresthereinside during diastolic function, and aiding in the pumping ofblood from the left ventricle during systolic function. Some embodimentsof the invention are further configured to limit ventricular dilatationin the treatment of systolic dysfunctions, wherein the limiting ofventricular dilatation may be activated at a later time after installingthe device on a patient's heart (also referred to herein as deviceshaving two operation modes).

In one preferred embodiment of the invention the ventricular functionassisting device is composed of elastic elements designed to be attachedto the wall of the left ventricle, and of restrictive elements (e.g.,rings or stripes) designed to be fastened over the heart of the patient.FIGS. 1A to 1X illustrate various preferred embodiments of a ventricularfunction assisting devices comprising elastic (or resilient) elements(43 or 54) having “V”-like shape (e.g., torsion springs), and in someembodiment also restrictive elements, 41 a and 41 b (shown in FIGS. 1Uand 1V), and tools that may be used for assisting in the attachment ofthese elements.

In this preferred embodiment ventricular function assisting device (40shown in FIGS. 1U and 1V) is designed to operate in two different modes.In the first mode of operation, device is attached to the patient'sheart such that elastic elements 43 attached over the left ventricleapply tangential and radial forces thereover during contractions andexpansions thereof, while the restrictive elements, 41 a and 41 b, arein a non-operative state, namely, said restrictive elements 41 a and 41b are placed around the patient's heart (10) such they do not interferewith its expansions.

The first mode of operation of device 40 is mainly directed for treatingdiastolic dysfunctions. During the systole elastic elements 43 arecompressed (the distance between their arms is reduced) as they storeelastic potential energy. During diastole, the elastic potential energystored in elastic elements 43 is released as they apply radial andtangential forces over their respective attachment elements 45.

In the second mode of operation of device 40 the perimeter ofrestrictive elements 41 is diminished by means of a fastening mechanism42 (42 a in upper restrictive element 41 a and 42 b in lower restrictiveelement 41 b) such that said restrictive elements 41 a and 41 b and thepatient's heart become engaged. The second mode of operation of device40 is mainly directed for treating systolic dysfunctions. As will beexplained hereinbelow the mode of operation of device 40 may be changedfrom the first mode to the second mode at a later time, after installingthe device. This configuration is particularly desirable in patientsinitially suffering from diastolic dysfunctions and which developsystolic dysfunction ailments during later treatment stages.

FIGS. 1A and 1B show a configuration of anchoring means 45 and elasticelements 43 suitable for use in the ventricular functions assistingdevice 40 (shown in FIGS. 1U and 1V). Elastic element 43 is preferably atype of torsion spring made from an elastic wire formed in a “V”-likeshape, having torsion loop(s) 30 at its apex and “G”-shaped anchoringloops 43 a at the end of its arms. Anchoring loops 43 a may have aspiral shape and they are preferably formed by bending the end sectionsof the arms towards spring loop(s) 30, thereby forming knees 43 k, andthereafter bending said end sections away from said spring loop(s) 30 toform a spiral shape therewith. In this way an “S”-like shape (marked bydotted line 4 in FIG. 1A) is formed at the end of each arm, wherein thebottom portion of the “S”-like shape is further curved to form the“G”-shaped curved fasteners 43 a.

As best seen in FIG. 1A, elastic element 43 comprises a first arm 14 awhich is relatively straight, and a second arm 14 b which is curvedrelative to the plain of the element. As shown in FIG. 1B, in theattachment of elastic elements 43 to attachment elements 45, second arms14 b of elastic elements 43 are curved such that the straight arm 14 aof the adjacent elastic element may be passed beneath the curved arm toengage the head section of the attachment element 45 while maintaining agap 39 therebetween.

As best seen in FIG. 1H, anchoring means 45 comprise a head section 45a, a neck section 45 b and an attachment section 45 c. Anchoring means45 are preferably made from a curved wire, wherein the attachmentsection 45 c is curved in a helix (spring) shape ending in a sharp tipfor facilitating threading thereof into the wall of the heart. Near theneck section 45 b of the anchoring means 45 the distances between thehelix loops are reduced abruptly to form the neck section 45 b, whichacts as a stopper to prevent excess threading of anchoring means 45.

Anchoring means 45 may be used for delivering medicaments into thetissue into which it is threaded. In such implementation the attachmentsection 45 b of anchoring means 45 may be coated by one or more layersof therapeutic medicaments, or alternatively, the attachment section 45b may be prepared to include an internal lumen, suitable for maintainingsaid medicaments thereinside, and release aperture communicating withsaid internal lumen, for releasing the medicaments into the tissuetherethrough. These drug delivery implementations may be designed forproviding delayed drug delivery to the tissue.

As exemplified in FIG. 1B, anchoring means 45 may be employed fordelivering electrical signal to the heart tissue by connecting apacemaker 85 thereto. Pacemaker 85 is a type of conventional pacemakerdevice which uses electrical impulses, typically delivered by electrodescontacting the heart muscles, to regulate heart beats. The primarypurpose of pacemaker 85 is to maintain an adequate heart rate, eithersince the heart's natural pacemaker (the sinus node) is not functioningproperly (i.e., slow heart beats), or if there is a block in the heart'selectrical conduction system. In some cases it may be advantageous tocombine with pacemaker 85 an implantable defibrillators, which isintegrated into a single implantable device. Other possibleimplementations may include multiple electrodes for stimulatingdifferent locations over the heart muscle to improve synchronization ofthe lower chambers of the heart. As shown in FIG. 1B, the pacemaker 85is electrically connected to loop 45 a of anchoring means 45 by means ofelectrical cable 85 w, wherein anchoring means 45 is implanted in theheart tissue and used as an electrical conductor for delivering theelectric signals produced by pacemaker 85 to the heart tissue.

It should be understood that pacemaker 85 may be implanted together withventricular function assisting device employing anchoring means 45, oralternatively, it may be implanted later, if required. Pacemaker 85 isimplanted in the patient's body in substantially the same way as inconventional pacemaker procedures, such that it may be placed under thechest or abdomen skin of the patient, but instead of using theconventional pacemaker electrodes the electrical signals it produces aredelivered to the patient's heart through anchoring means 45.

The head section 45 a is formed in a shape of a loop through which the“G”-shaped anchoring loops 43 a of the elastic elements 43 can be passedto engage the same therein. Head section 45 a may be formed in anysuitable geometrical shape e.g., circular, elliptic, rectangular,however, in this preferred embodiment the head section 45 a is formed ina shape of a ring.

Anchoring means 45 (also shown in FIG. 1H) can be threaded into the wallof the heart by rotation. The attachment method of elastic elements 43and anchoring means 45 is shown in FIG. 1B, wherein two elastic elements43 are mounted by means of attachment elements 45.

Elastic element 43 may be manufactured using conventional wire (e.g.,having circular, elliptic, or rectangular/polygonal cross section)curving techniques, photo chemical etching techniques, laser cutting, orby an erosion process (e.g., using tin films) from a type of elasticmetal or plastic, such as, but not limited to, Nitinol, stainless steel,silicon, or a suitable alloy, composite compound, or absolvable material(e.g., PLLA, PGA, or PLA), preferably from a Cobalt alloy, having adiameter (thickness) of about 0.45 mm. The length of the arms of elasticelement 43 may generally be in the range of 20 to 30 mm, preferablyabout 23 mm, and the angle α therebetween is about 165±5°. The diameterof torsion loop(s) may generally be in the range of 3.5 mm (for elasticelements mounted at the extremities of the lined sequence) to 5.7 mm,and the diameter of the “G”-shaped anchoring loops 43 a is preferablyabout 2±1 mm.

Anchoring means 45 may be manufactured by using conventional springmanufacturing techniques, wire curving processes which may be followedby a suitable thermal treatment to set mechanical characteristics andrelax curving tensions. Anchoring means 45 may be manufactured from atype of metal or plastic material, such as, but not limited to, Nitinol,stainless steel, silicon, or a suitable alloy, composite compound, orabsolvable material (e.g., PLLA, PGA, or PLA), preferably from, a Cobaltalloy. Most preferably, anchoring means 45 are made from a turned wirehaving thickness of about 0.45 mm and made of a Cobalt alloy. The totallength of anchoring means 45 may generally be in the range of 8 to 18mm, preferably about 15 mm. The diameter of the helix loops in theattachment section 45 c may generally be in the range of 3 to 6 mm,preferably about 5 mm, the distance between consecutive loops thereofmay generally be in the range of 1 to 3 mm, preferably about 2 mm, andthe length of said attachment section may generally be in the range of 6to 12 mm, preferably about 8 mm. The diameter of the neck section 45 bmay generally be in the range of 2 to 6 mm, preferably about 5 mm, andits length may generally be in the range of 0.5 to 2 mm, preferablyabout 1.5 mm.

A product comprising elastic elements and anchoring means suitable forventricular function assisting device 40 is sold under the ImCardiatrademark of CorAssist cardiovascular Ltd., Israel.

Another possible configuration of elastic elements and anchoring meansis depicted in FIGS. 1C to 1F. In this preferred embodiment theattachment section 53 c and the neck section 53 b of the anchoring means53 are made from a curved wire, while its head section 53 m is made froma flanged rod comprising a flanged base 53 g adapted to firmly fit intothe loops of neck section 53 b, a flanged top 53 h, and a middle flange53 f therebetween. The gaps 53 q and 53 r respectively obtained in headsection 53 m between flanged base 53 g and middle flange 53 f, andbetween flanged top 53 h and middle flange 53 f, are adapted to receive“C”-shaped graspers 54 u of elastic element 54. Elastic element 54 ispreferably a type of torsion spring made from an elastic wire formed ina “V”-like shape, having torsion loop(s) 54 r at its apex and “C”-shapedgraspers 54 u at the end of its arms 54 a. The wire at the tips of“C”-shaped graspers 43 a is preferably shaped to form fastening loops 54q adapted to provide firm attachment over the flanged rod 53 m. Flangedrod 53 m is preferably attached to neck section 53 b of anchoring means53 by welding.

FIG. 1F demonstrates attachment of neighboring elastic elements 54 to amutual anchoring means 69. The attachment section 69 c, neck section 69b and head section 69 a, of anchoring means 69 are preferably made froma single wire turned such that the shape of head section 69 a is similarto the shape of flanged rod (53 m) in anchoring means 53, by forming anexpanded top 69 h and expanded middle 69 f such that corresponding gaps69 q and 69 r are obtained suitable for receiving the graspers of theelastic element.

FIG. 1E illustrates one preferred embodiment of an anchoring means 55having attachment section 55 c and neck section 55 b made from a curvedwire, and a head section 55 m made from a flanged rod, as in anchoringmeans 53 (shown in FIG. 1D) described hereinabove, and furthercomprising domelike top 55 z screwed into the flanged top 55 h ofanchoring means 55 for protecting and preventing tissue injury. In thisexample elastic elements 54′ are attached to anchoring means 55 by meansof closed loops provided on its arms and which are fitted into the gapsformed in head section 55 m. Elastic elements 54′ and anchoring means 53may be manufactured from similar materials, and by means of similartechniques, as in the respective means previously described hereinabove.

FIG. 1G shows a perspective view of a guiding tool 68 suitable forguiding the operator in the positioning of the anchoring means of theinvention. Guiding tool 68 comprises an elongated handle 68 r and alocator portion 68 y attached to its distal end. Locator portion 68 ycomprises two perpendicular arms used for designating the distancebetween adjacent anchoring means. In use, the arm having a curved end 68c will typically be engaged in the attachment section of the anchoringmeans (e.g., 45 c of anchoring means 45) while the arm comprising thevertical ending 68 u will be used to guide the operator in determining alocation for a new anchoring means to be attached. Guiding tool 68 maybe manufactured from stainless steel, nitinol, or from a biocompatiblealloy, by extrusion or a metal working process, for example. The lengthof guiding tool 68 may generally be in the range of 180-200 mm, itsdiameter about 1 to 2 mm, and the width of locator portion 68 y may beabout 30 to 70 mm.

FIGS. 1H to 1O illustrate and demonstrate attachment of the anchoringmeans 45 depicted in FIG. 1H by means of a screwing tool 57. Withreference to FIG. 1J, screwing tool 57 comprises a proximal handle 57 hto which there is attached a hollow shaft 57 s having a hinged head 57 dconnected thereto by hinge 57 i. Proximal handle 57 h comprises arotatable wheel 57 w mounted in depressions 57 e provided in opposingsides of proximal handle 57 h. Screwing tool 57 may further comprise afoldable locator 57 g for aiding the operator in determining locationsfor screwing the anchoring means 45 over the heart wall. In FIG. 1Jfoldable locator 57 g is shown in its deployed state, if however it isnot needed, it may be rotated about the hinges connecting it to hingedhead 57 d, such that it is placed over and aligned with a side surfacethereof.

With reference to FIG. 1L, illustrating a sectional view of screwingtool 57, hinged head 57 d comprises a distal opening 57 o adapted toreceive and hold a holding cup 56 in which anchoring means 45 is held bymeans of a fastening rod 58. The base of holding cup 56 is firmlyreceived in rotatable holder 57 z rotatably mounted inside hinged head57 d, on its base. Hollow shaft 57 s comprises a rotatable rod 57 qplaced thereinside mechanically linked to rotatable wheel 57 w. At thedistal end of rotatable rod 57 q there is attached one end of a wire (orflexible rod) 57 r, which other end is attached to rotatable holder 57 zprovided inside hinged head 57 d. In this way rotary motion of wheel 57w is delivered via rod 57 q and wire 57 w to rotatable holder 57 z,which in turn delivers the rotary motion to the fastening rod 58 andanchoring means 45 assembly held by holding cup 56.

FIG. 1K shows a perspective view of fastening rod 58 having an anchoringmeans 45 attached to it. As shown, fastening rod 58 comprises a centralslit 58 s passing along a longitudinal section of its length. Centralslit 58 s is adapted to receive and firmly hold the head section (45 a)of anchoring means 45. FIG. 1I shows a perspective view of holding cup56 holding a fastening rod 58 (not shown) and anchoring means 45assembly, wherein it is seen that holding cup 56 is made from agenerally a cylindrical element 56 c having flanged edge 56 f over itsopening 56 p, which is adapted to receive said fastening rod 58 andanchoring means 45 assembly.

FIGS. 1M and 1N, are exemplifying attachment of anchoring means by meansof screwing tool 57. During this process the operator adjusts the angleof hinged head 57 d to allow its front side to face and access the heart10, and then the anchoring window 57 n of locator 57 g is placed over apreviously placed anchoring means 45, thus providing a tolerance fordetermining a suitable location for attaching the new anchoring means.Once the new location is determined the operator gently presses thefront side of hinged head 57 d of screwing tool 57 against the wall ofthe heart 10 and rotates wheel 57 w, thereby screwing anchoring means 45into the tissue.

Screwing tool 57 may be manufactured from stainless steel, Teflon,nitinol, polycarbonate, silicon, medical grade delrin, medical gradenylon, or from a biocompatible alloy, by means of extrusion, rapidprototyping, or metal working, for example. The length of screwing tool57 may generally be about 200-500 mm and its diameter about 10-40 mm.

FIGS. 1O to 1Q illustrate a preferred embodiment of a tool 60 designedfor delivering and attaching several anchoring means 45 stacked inseries inside its hollow shaft 60 s configured as a stack having alongitudinal slit 60 i along its length adapted to slidably hold thehead sections (45 a) of anchoring means 45. The anchoring means 45 arepushed distally by spring 60 p and the most distal anchoring means 45stacked inside shaft 60 s is attached to a screwing head 60 t configuredto hold the head section 45 a of the anchoring means 45 and rotate itwhen push-button 60 d in proximal handle 60 h is pressed by theoperator. Whenever pressed down, push-button 60 d activates anelectrical motor (not shown) configured to deliver rotational motion toscrewing head 60 t.

As seen in FIG. 1O, tool 60 further comprises a movable rod 60 a passingalong the length of its bottom side, said movable rod 60 a ismechanically linked to slider 60 r. With reference to FIG. 1Q, showing atop view of the proximal section of tool 60, slider 60 a may be changedbetween two operation states, by retaining it in lateral slit 60 q or inlateral slit 60 r. Locator 60W is placed over a previously placedanchoring means 45, thus providing an anchor for determining a suitablelocation for attaching the new anchoring means. Once the new location isdetermined the operator gently push the movable rod 60 a into thelateral slit 60 q and push-button 60 d in proximal handle 60 h tooperate the delivery tool 60 for implantation a new anchoring means 45.

As seen in FIG. 1O, the distal part of hollow shaft 60 s may compriseoptical guiding means 60 g mounted on opposing sides thereof and adaptedto emit light beams (e.g., by means of low-energy laser diodes) set inproper angles such that one light beam can point to a new location forplacing a new anchoring means whenever the other light beam is placedover the location of a previously placed anchoring means, thereby aidingthe operator in determining a proper distance between the anchoringmeans.

It is noted that the delivery tools 57 and 61 described hereinabove maybe easily modified for delivering and attaching various embodiments ofthe anchoring means, such as anchoring means 69 (shown in FIG. 1F),anchoring means 53 (shown in FIG. 1D), described hereinabove, andmodifications thereof.

FIGS. 1R to 1T show various views of a delivery tool 59 designed fordelivering an elastic element 43 (or other such elastic elements, suchas for example, 43 shown in FIG. 1A, 54 shown in FIG. 1C, or 54′ shownin FIG. 1E) and attaching the same over previously placed anchoringmeans in a minimally invasive procedure. With reference to FIG. 1R,delivery tool 59 comprises a hollow handle 59 h having a longitudinalslit 59 s passing along a portion of its length in which there ismovably placed a slider element 59 p, a slidable shaft 59 f extendingdistally therefrom and which proximal portion is placed inside hollowhandle 59 h and mechanically linked to slider element 59 p by means ofslidable connector 59 c, and a longitudinal rod 59 r fixedly attached tohandle 59 h at 59 n and passing inside, and along the entire lengths of,hollow handle 59 h and slidable shaft 59 f. The distal end oflongitudinal rod 59 r comprises a retaining part 59 k configured toreceive and hold the torsion loop(s) (30) of the elastic element.

As seen in FIG. 1R longitudinal slit 59 s comprises a proximal recess 59b and a distal recess 59 y in each of which slider element may beplaced. In a first state of device 59, shown in FIGS. 1R to 1T, sliderelement 59 p is held in proximal recess 59 b, in which state slidableshaft 59 f is pulled proximally such that retaining part 59 k is exposedthrough distal end opening of slidable shaft 59 f. In a second state ofdevice 59 (not shown) slider element 59 p is held in distal recess 59 y,in which state slidable shaft 59 f is pushed distally such that slidableshaft 59 f is pushed distally and retaining part 59 k is introduced intochamber 59 g provided inside slidable shaft 59 f at its distal end.

In FIG. 1T there is shown an enlarged view of the distal portion ofdelivery tool 59 when an elastic element 43 is retained in its retainingpart 59 k. As seen, retaining part 59 k comprises of flat section 59 eon which there is a holding shoulder 59 y which upper protrusion isfacing slidable sheath 59 f, and a tooth 59 x formed at its distal end.The distance between shoulder 59 y and tooth 59 x is configured suchthat torsion loop(s) 30 of the elastic element 43 are retained thereoverby placing apex of the “V”-shaped elastic element 43 under the upperprotrusion of shoulder 59 y and the opposing side of torsion loop(s) 30over tooth 59 x. In this way, when slider element is placed in distalrecess 59 y slidable shaft 59 f is pushed over retaining part 59 k andelastic element 43 held by it, such that arms 14 a and 14 b of elasticelement 43 are bent distally into chamber 59 g.

In this way the elastic element 43 is delivered in a folded state (notshown) through a small incision and attached to the anchoring meanspreviously placed on the heart by placing the distal end of tool 59 nearthe previously attached anchoring means and moving slider element 59 pback to proximal recess 59 b, which in turn retracts slidable shaft 59 fproximally and exposes elastic element out of chamber 59 g. The operatorthen simply maneuvers tool 59 and slider element 59 p for properlyengaging “G”-shaped anchoring loops 43 a of elastic element 43 (orC-shaped graspers 54 u of elastic element 54) in head sections 45 a ofanchoring means 45, as illustrated in FIG. 1B.

Delivery tool 59 may be manufactured from stainless steel, Teflon,nitinol, polycarbonate, silicon, medical grade delrin, medical gradenylon, or from a biocompatible alloy, by means of extrusion, rapidprototyping, or metal working, for example. The length of delivery tool59 may generally be about 200-500 mm and its diameter about 10-40 mm.

FIG. 1U shows a perspective view of one preferred embodiment ofventricular function assisting device 40. Device 40 is configured toencircle the heart 10 (shown in FIG. 1V) by at least two, upper andlower, restrictive elements, 41 a and 41 b, respectively. The upper andlower restrictive elements, 41 a and 41 b, are connected by means ofsprings 46 to a set of vertical bars 47 equally distributed about theperimeters of restrictive elements 41 a and 41 b. Springs 46 may bepulling and/or pushing springs and they are mainly used when device 40is operated in the second mode of operation i.e., after restrictiveelements, 41 a and 41 b, are secured to the wall of the heart by meansof fastening mechanisms, 42 a and 42 b, respectively. Vertical bars 47are preferably curved according to the curvature of the heart, but themay also be flexible enough to allow them to easily curve and assume acurvature more or less similar to the curvature of the heart.

Vertical bars 47 are attached to the wall of the heart by means ofanchoring means 45 threaded into the wall of the heart 10 along theirlengths. Vertical bars 47 are passed through the head sections (45 a) ofanchoring means 45, such that minimal or negligibly small forces areapplied over the wall of the heart by vertical bars 47 at the attachmentpoints of anchoring means 45 when device 40 is operated in the firstmode of operation.

The portion of device 40 mounted over the left ventricle furthercomprises elastic elements 43 which are mounted more or lesshorizontally between pairs of adjacent anchoring means attached to thewall of ventricle. Restrictive elements, 41 a and 41 b, comprises afastening mechanisms, 42 a and 42 b, respectively, which are initiallyin a state which allows encircling the heart by restrictive elements 41a and 41 b without engaging the heart by said restrictive elements 41 aand 41 b. Fastening mechanisms 42 a and 42 b are configured to allowfastening restrictive elements over heart 10 at a later time after themounting procedure of device 40 on the heart is completed.

In this way the operation of device 40 may be changed into its secondmode of operation whenever needed, particularly if the patient developssystolic dysfunctions. The activation of fastening mechanisms, 42 a and42 b, may be carried out by a minimally invasive procedure, for example,via a small incision, by connecting access tubes to device 40 eachhaving one opening near fastening mechanism (e.g., 42 a) and anotheropening being externally accessible by the practitioner such thatsuitable instruments (e.g., clamps, tweezers) may be introducedtherethrough for fastening restrictive elements over the heart.

FIG. 1V show the ventricular function assisting device 40 illustrated inFIG. 1U, when mounted on a heart 10. FIG. 1W illustrates a possibleimplementation of a locking mechanism 42 a (or 42 b) suitable forfastening the ventricular function assisting device 40 over the heart10. In this implementation a pulling spring 50 is mounted over a gap 41g in restrictive element 41 a. Pulling spring 50 may be mounted by meansof two socket members 51 formed, or attached, on restrictive element 41a near gap 41 g, and having respective sockets 51 s capable of receivingspring ends 50 e and securing the same to restrictive element 41 a.

Locking mechanism 42 a further comprises a supporting bar 52 configuredto attach to restrictive element 41 a over the opening of gap 41 g. Inthis way gap 41 g is maintained in restrictive element 41 a due tosupporting bar 52, which prevents its closure by pulling spring 50.Supporting bar 52 comprises attachment pins 52 b provided at its ends,said attachment pins 52 b are more or less perpendicular to supportingbar 52 for allowing them to be received in respective sockets 41 sprovided in the opposing sides of restrictive element 41 a, having gap41 g there between. Grip 52 g is attached, or formed, perpendicular tosupporting bar 52 more or less about its center, for providing thepractitioner a convenient grip for removing supporting bar 52 when thefastening of restrictive element 41 a over heart 10 by the closure ofgap 41 g is needed, as shown in FIG. 1X. Conveniently, grip 52 g mayinclude a head portion 52 h for improving the grip there over.

Restrictive elements 41 may be manufactured from a biocompatiblemetallic alloy, for example, from stainless steel or from abiocompatible polymer, for example silicon, preferably from stainlesssteel. The lengths of restrictive elements 41 should be adjustedaccording to the size of the treated heart, for example, the length ofupper restrictive element 41 a may generally be in the range of 115 to145 mm, preferably about 125 mm, and the length of lower restrictiveelements 41 b may generally be in the range of 10 to 120 mm, preferablyabout 50 mm.

Vertical bars 47 may be manufactured from a biocompatible metallicalloy, for example stainless steel or Conichrome (fwm 1058) or from abiocompatible polymer, for example silicon, preferably from stainlesssteel. The lengths of vertical bars 47 may generally be in the range of70 to 120 mm, preferably about 90 mm. Springs 46 are preferably smallsprings made from a biocompatible metal alloy, for example stainlesssteel or Conichrome (fwm 1058), configured to apply forces in the rangeof 0.7 to 1.2 N.

Referring now to FIG. 1W, Pulling spring 50 is preferably made from anelastic wire having a diameter generally in the range of 0.3 to 0.7 mm,preferably about 0.5 mm, and it is preferably made flat (e.g., havingelliptic or rectangular spring loops) in its cross-sectional profile.Spring 50 may be manufactured by conventional spring manufacturetechniques, from a type of biocompatible metallic alloy, for examplestainless steel or Conichrome (fwm 1058), preferably from Conichrome.The length of spring 50 may generally be in the range of 10 to 20 mm,preferably about 15 mm.

Gap 41 g may generally be in the range of 5 to 20 mm, preferably about10 mm. Supporting bar 52 may be manufactured from a biocompatiblemetallic alloy, for example stainless steel or Conichrome (fwm 1058),preferably from Conichrome. The diameter of supporting bar 52 maygenerally be in the range of 1 to 3 mm, preferably about 2 mm, and itslength should be fitted to the length of gap 41 g.

Ventricular function assisting device 40 may be mounted on the heart ofa treated subject in a procedure comprising the following steps: firstin open chest surgery followed by thoracotomy, and at a later stage,when the systolic device needs to be functional, this may be performedutilizing minimal invasive thoracoscopy procedure. Normally, device 40will be installed in its first mode of operation for treating diastolicdysfunctions. If at a later time the patient develops systolicdysfunction ailments the state of the device may be changed to operatein its second mode of operation by fastening restrictive elements 41over the heart. The fastening of restrictive elements 41 may be carriedout as follows: pull out the pin 52 by minimal invasive procedure andthereby causing restrictive elements 41 to fasten over the heartautomatically.

Of course, device 40 may be installed on the heart of a treated subjectinitially in its second mode of operation, if treatment of both,diastolic and systolic dysfunctions is required.

In the example illustrated in FIGS. 1C and 1D, only two restrictiveelements (41 a and 41 b) are shown, however, it should be clear thatembodiments of the invention may include more than two such elements.

FIGS. 2A and 2B schematically illustrate an embodiment of theventricular function assisting device 61 for treating systolic anddiastolic dysfunctions, in which the restrictive elements 65 a and 65 bare implemented by tension springs (for example, having a wavyconfiguration) which increase their elasticity. Although in the figuresonly two such restrictive elements are illustrated, it should be clearthat embodiments of the invention may include more than two suchelements. FIG. 2A shows the side of device 61 which is installed overthe right ventricle and FIG. 2B shows the other side of the device,which is installed over the left ventricle of the heart. In thisembodiment vertical bars 47 may be connected directly to tension springs65 a and 65 b, or by means of springs (not shown), as exemplified inFIGS. 1C and 1D.

Device 61 may be installed on the wall of the heart of a treated subjectby means of anchoring means 45, as exemplified in FIGS. 1A to 1D, andcan partially or completely circumvent the heart. Preferably, theoperation of device 61 may be changed between two operation modes bymeans of fastening mechanisms (e.g., 42 a demonstrated in FIGS. 1W and1X) provided in its restrictive elements 65 a and 65 b (not shown), asexemplified hereinabove.

Alternatively, the embodiment shown in FIGS. 2A and 2B the ventricularfunction assisting devices 61 may be operated in only one mode ofoperation, in which both diastolic and systolic dysfunctions aretreated. Namely, after device 61 is installed on the wall of the heartof the patient, the operations of both the elastic elements 43 and ofthe restrictive elements 65 a are effective.

FIGS. 3A and 3B schematically illustrate ventricular function assistingdevices, 63 and 64, respectively, for treating systolic and diastolicdysfunctions, which employ intermediate restrictive elements, 65 c and41 c, respectively. In these embodiments shorter vertical bars 47 s areused for connecting between the restrictive elements. For example, inFIG. 3A, vertical bars 47 s are used for connecting upper restrictiveelement 65 a to intermediate restrictive element 65 c, and forconnecting lower restrictive element 65 b to intermediate restrictiveelement 65 c. As previously explained, any number of such restrictiveelements may be used, and the number of elements shown in FIGS. 3A and3B is provided by way of example only.

Vertical bars 47 s may be connected to the restrictive elements by meansof springs 46 s. Furthermore, the lengths of vertical bars 47 sconnecting between the upper restrictive element (e.g., 41 a) and theintermediate restrictive element (41 c) may be different from thelengths of vertical bars 47 s connecting between the lower restrictiveelement (e.g., 41 b) and the intermediate restrictive element (41 c).

In the device 63 shown in FIG. 3A restrictive elements 65 have a wavyconfiguration for increasing their elasticity. Restrictive elements 65a, 65 b and 65 c, may be manufactured from a cobalt alloy or stainlesssteel, preferably from Conichrome (fwm 1058). As in the embodimentillustrated in FIGS. 2A and 2B, device 63 may be operated in only thesecond mode of operation, in which both diastolic and systolicdysfunctions are treated. Device 63 may be similarly attached to thewall of the heart by means of anchoring means (45 not shown).

The device 64 shown in FIG. 3B is principally similar to the deviceshown in FIGS. 2A to 2D, where the main differences are in the use ofintermediate restrictive element 41 c, and connecting the same torestrictive elements 41 a and 41 b by means of shorter vertical bars 47s.

FIGS. 4A to 4C schematically illustrates an implementation of aventricular function assisting device 77 for treating combined systolicand diastolic dysfunctions which is configured to enclose the apex ofthe heart 10. As illustrated in the perspective view shown in FIG. 4A,device 77 comprises a single restrictive element 41, and as more clearlyseen in the side view shown in FIG. 4C, vertical bars 47 are forming aclosed connection point 48 at the bottom of device 77 (e.g., by means ofcylinder pivot or a kind of joint).

FIG. 4B schematically illustrates a possible fastening mechanism basedon threading. In this example, the fastening mechanism is based on asimple screw tightening method (e.g., gear clamp), wherein screw 42 t isused for tightening (or for loosening) restrictive element 41 aboutheart 10. This mechanism may be manufactured from biocompatiblematerials similar to those discussed hereinabove, preferably fromstainless steel, employing conventional standard manufacture techniques.

FIGS. 5A and 5B schematically illustrate a device 80 for treatingsystolic and diastolic dysfunctions which is based on a magneticmechanism. Device 80 comprises an upper restrictive element 41 a and alower restrictive element 41 b which are connected by means of curvedvertical bars 47. Vertical bars 47 provide a support for a set of one ormore horizontal rings 49 encircling heart 10. Each horizontal ring 49comprises a set of electromagnets 81 a, each of which is connected to acontrollable power source (e.g., current source, piezoelectric, notshown). A corresponding set of permanent magnets 81 b is attached to thewall of the heart 10 opposite to electromagnets 81 a, such that pairs ofadjacent electromagnets 81 a and permanent magnets Bib are obtained.

As exemplified in FIG. 5B, which shows a portion of device 80 withoutheart 10, permanent magnets 81 b may be attached to the wall of theheart 10 by means of anchoring means 45, or by a modification or any ofthe various variations thereof exemplified hereinabove, adjusted toinclude a permanent magnet 81 b at their head section (45 a not shown).Control means (not shown) is used to control the operation of the powersource used for energizing electromagnets 81. In cases of systolicdysfunctions, during systole, the control means operates the powersource to activate electromagnets 81 a such that the polarity of themagnetic field produced thereby causes repulsion forces to evolvebetween electromagnets 81 a and permanent magnets 81 b, in order toassist the systolic heart contraction. In cases of diastolicdysfunctions, during diastole, the control means operates the powersource to activate electromagnets 81 a such that the polarity of themagnetic field produced thereby causes attraction forces to evolvebetween electromagnets 81 a and permanent magnets 81 b, and therebyassist in the diastolic heart expansion.

Of course, the operation of the electromagnets should be synchronizedwith the heart activity. The synchronization may be achieved bymonitoring ECG signal, signals received from a pacemaker, or by means ofa suitable internal sensor.

Horizontal rings 49 may be manufactured from the same material ofvertical bars 47, and they may be attached to said vertical bars 47 by arigid or non-rigid connection. The pairs of electromagnets 81 a andpermanent magnets 81 b are adapted to produce repulsion/attractionforces generally in the range of 0.7 to 1.2 N. Permanent magnets 81 bmay be manufactured from a magnet with biocompatible cover.Electromagnets 81 a may be implemented by small coils having a core madefrom a paramagnetic or ferromagnetic material (e.g., magnesium,molybdenum, lithium, or tantalum); said coils may be manufactured fromcopper. The distances between electromagnets 81 a and permanent magnets81 b may generally be in the range of 0 to 10 mm.

In another preferred embodiment of the invention the ventricularfunction assisting device is based on a plunger mechanism designed to—i)augment the relaxation of the left ventricle of the heart duringdiastolic phase, which assists in reducing the pressure thereinside andin pumping blood thereinto; and ii) help the left ventricle duringsystolic function, to pump out the blood from said ventricle.

The plunger mechanism device generally consists of two hollow sections,a front section and a rear section, which interiors are communicated bya mutual opening, wherein said hollow sections comprise mechanicallylinked slidable plungers installed in each of said sections. The hollowsections and their respective plungers are aligned along a longitudinalaxis of the device (also referred to as axis of movement) such that saidplungers are free to move thereinside along said longitudinal axis. Theplungers are mechanically linked to an elastic or shape memory device,preferably in a form of a spring, which is adapted for applyingmechanical forces on said plungers for sliding the same in theirrespective sections.

The front and rear hollow sections of the device are designed tocommunicate with a chamber of the heart and to pump in, and pump out,volumes of blood from/to said chamber. The front hollow section of thedevice comprises a front opening, preferably aligned with the axis ofmovement of the plungers, adapted to communicate with a chamber of theheart via a first aperture in the wall of the heart. The rear hollowsection of the device comprises a lateral opening which is adapted tocommunicate with the chamber of the heart via a tube, said tube beingconnected to said lateral opening at one end thereof and to a secondaperture in the wall of the heart by another end thereof.

The plungers may be mechanically linked by a rod connecting between thecenters of said plungers. The surface areas of the plungers are designedsuch that different forces are applied thereover responsive to thepressure in the chamber of the heart to which the device is connected.More particularly, the surface area of the plunger installed in thefront hollow section is configured to be smaller than the surface areaof the plunger installed in the rear hollow section of the device, andthe cross sectional area of said hollow sections is configuredcorrespondingly to snugly fit over said plungers. The elastic/shapememory device is adapted to apply mechanical forces over the plunger'sassembly (the plungers and the rod connecting them) for pushing the sametowards the rear section of the device.

The different surface areas of the plungers and the forces applied bythe elastic/shape memory device are designed such that during diastolicfunction the forces applied over the front plunger by the blood pressurein the chamber of the heart and by the elastic/shape memory (pushingspring) device force the plungers assembly to move towards the rearsection of the device, thereby increasing the volume of the heartchamber, assisting in pumping blood thereinto, and reducing the pressurethereinside. During the systole function, due to the increased bloodpressure, the forces applied over the rear plunger are greater than theforces applied over the front plunger by the blood pressure and theelastic/shape memory (pushing spring) device, such that the plungersassembly is forced to move toward the front section of the device,thereby reducing the volume of the heart chamber and assisting inpumping out blood therefrom.

FIGS. 6A and 6B schematically illustrate the structure and operation ofone preferred embodiment of a ventricular function assisting device 12based on a plunger mechanism. Ventricular function assisting device 12comprises a front hollow section 12 f and a rear hollow section 12 rhaving a mutual opening 12 m connecting their interiors. Front plunger14 f is slidably installed inside front hollow section 12 f, and rearplunger 14 r is slidably installed inside rear hollow section 12 r. Rod15 is used for connecting the center of front plunger 14 f to the centerof the rear plunger 14 r.

Front hollow section 12 f of the device 12 comprises a front opening 12o adapted to communicate with the interior of the heart 10 via a firstaperture 10 b formed in heart 10. Support 19, preferably implemented bya rod, is mounted in front opening 12 o to provide a support for spring13 (pushing spring) mounted thereon, such that spring 13 is capable ofapplying mechanical forces over front plunger 14 f along a longitudinalaxis 6 of device 12. Tube 17 communicates with the interior of rearhollow section 12 r via a lateral opening 121 provided in said rearsection 12 r. Tube 17 comprises an angled or curved section which moreor less aligns opening 17 o of tube 17 with opening 12 o of front hollowsection 12 f. Opening 17 o is adapted to communicate with the interiorof heart 10 via a second aperture 10 a formed in the wall of heart 10.

In one specific preferred embodiment of the invention (not shown) thepressure changes in heart 10 are affected inside ventricular functionassisting device 12 via tube 17 by means of intermediate means, suchthat blood is not flown through the entire length of tube 17. In onepossible implementation pressure sensors are used for measuring thepressure in the openings 121 and 10 a, and pressure inside ventricularfunction assisting device 12 is adjusted accordingly. Alternatively,pressure changes may be affected in ventricular function assistingdevice 12 by filling tube 17 with a type of biological fluid (noncompressible) capable of transferring the pressure changes into device12. In yet another implementation, springs and plunger assembly may beused to transfer the pressure from lateral opening 121 to secondaperture 10 a.

The front and rear plungers, 14 f and 14 r, are designed such thatdifferent powers are applied there over by the blood pumped in and outof heart 10. For this purpose the surface area (A_(f), e.g., 78 to 710mm²) of front plunger 14 f is made smaller relative to the surface area(A_(r), e.g., 78 to 710 mm²) of rear plunger 14 r. Spring 13 isconfigured to apply forces (e.g., F_(x), e.g., 1 to 10 N) over frontplunger 14 f which enables the plungers assembly to slide alonglongitudinal axis 6 responsive to pressure variations in heart chamberto which the device is connected.

FIG. 6A illustrates the operation of the device 12 during the diastole,in which the pressure in the heart chamber is reduced such that the sumof forces applied over the front plunger 14 f due to the diastolicpressure (P_(d)) in the heart chamber (P_(s)·A_(f)) and by spring 13(F_(x)), is greater than the force applied over rear plunger 12 r due tosaid diastolic pressure (P_(d)) i.e., P_(d)·A_(f)+F_(x)>P_(d)·A_(r). Inresponse, the plungers' assembly (i.e., front plunger 14 f, rear plunger14 r, and rod 15 connecting them) is forced to slide towards rearsection 12 r of device 12. As demonstrated by arrows 8 i the rearwardmovement of the plungers assembly increases the chamber volume andassists in pumping blood thereinto. In response, portion of the blood indevice 12 is discharged into heart 10, as demonstrated by arrows 7 o.

FIG. 6B illustrates the operation of the device 12 during the systole,in which the pressure in the heart chamber is increased such that thesum of forces applied over the front plunger 14 f due to the systolicpressure (P_(s)) in the chamber (P_(s)·S_(f)) and by spring 13 (F_(x)),is smaller than the force applied over rear plunger 14 r due to saidsystolic pressure (P_(s)) i.e., P_(s)·A_(f)+F_(x)<P_(s)·A_(r). Inresponse, the plunger assembly is forced to slide towards front section12 f of device 12. As demonstrated by arrows 8 o, this movement of frontplunger 14 f assists in pumping out blood from the ventricle. Inresponse, a volume of blood is pumped into device 12 via tube 17, asdemonstrated by arrows 7 i.

FIG. 7A shows a perspective view of a ventricular function assistingdevice 12, as illustrated in FIGS. 6A and 6B, wherein the front section12 f and the rear section 12 r are implemented by two sealably connectedhollow bodies. In this embodiment spring 13 (not shown) is mounted on asmall disk 9 provided on supports 19. FIG. 7B is a longitudinal-sectionview illustrating an embodiment wherein pulling spring 13 a is used,said pulling spring 13 a is mounted in a spring enclosure 13 e providedbetween rear plunger 14 r and a rear wall 12 w of rear section 12 r.Spring 13 a is sealably enclosed in spring enclosure 13 e to prevent theblood moving in device 12 from contacting the spring.

FIG. 8A is a longitudinal-section view of an embodiment of the diastolicfunction assisting device of the invention wherein the interior of thefront section 12 f communicates with the interior of the heart via ashort tube 18. In this embodiment front section 12 f comprises a frontwall 18 w used for closing the front side of front section 12 f, whereinsaid front wall 18 w has a tapering shape and comprises an opening (notshown) adapted to communicate with tube 18. Tube 18 and wall 18 w areadapted to be attached to the wall of the heart 10, as illustrated inFIG. 8E. In this configuration Blood may be flown via an opening 18 o oftube 18, into, or out from, device 12. FIG. 8E is a longitudinal sectionview of the embodiment shown in FIG. 8A showing said device mounted onthe wall of the heart 10.

FIG. 8B is a longitudinal-section view illustrating an embodiment ofdevice 12 configured to be connected to the wall of the heart 10 bymeans of front wall 18 w and tube 18, as in FIG. 8A, wherein pullingspring 13 a is used, said pulling spring 13 a is mounted between rearplunger 14 r and rear wall 12 w of rear section 12 r. FIG. 8Cillustrates a longitudinal section view of this embodiment when mountedon a wall of heart 10.

FIG. 8D is a longitudinal-section view of an embodiment of device 12configured to be connected to the wall of the heart 10 by means of frontwall 18 w and tube 18, as in FIG. 8A, wherein pulling spring 13 a ismounted in a spring enclosure 13 e between rear plunger 14 r and rearwall 12 w of rear section 12 r. Spring enclosure 13 e may be a typeflexible tube made of silicon, polyurethane, or any kind of flexiblepolymer, suitable for sealing spring 13 a and preventing blood fromcontacting it.

Ventricular function assisting device 12 may be manufactured, forexample, by machining or injection, from type of biocompatiblematerials, such as for example, stainless steel, cobalt alloy, silicon,or Teflon, preferably from stainless steel. Spring 13 (or pulling spring13 a) may be manufactured from a suitable type of elastic or shapememory material, such as, but not limited to biocompatible metal alloy,preferably from stainless steel. The length of spring 13, or of pullingspring 13 a, may generally be in the range of 5 to 25 mm, preferablyabout 15 mm, and its diameter may generally be about 0.1 to 1 mm.

Front hollow section 12 f is preferably made from a cylindrical bodyhaving a diameter generally in the range of 10 to 30 mm and a lengthgenerally in the range of 5 to 25 mm. Rear hollow section 12 r ispreferably also made from a cylindrical body having a diameter generallyin the range of 15 to 45 mm and a length generally in the range of 5 to25 mm. Front and rear sections may be manufactured as integral parts ofdevice 12, or alternatively, as separate parts which may be connected,for example, by means of screws.

Tube 17 is preferably manufactured as an integral part of rear section12 r, and it may be manufactured from the same material said rearsection is made from. Similarly, tube 18 and front wall 18 w arepreferably manufactured as integral parts of front section 12 f, andthey are made from the same material from which said front section ismade.

Front and rear plungers, 14 f and 14 r, may be implemented by bodieshaving a disk shape made from stainless steel or silicon, preferablyfrom silicon, adapted to be slidably installed in front and rear hollowsections, 12 f and 12 r, respectively.

FIGS. 9A and 9B schematically illustrate a ventricular functionassisting device 90 employing an electromagnetically driven plunger 93.Device 90 is preferably made from a hollow cylindrical body whichinterior may be accessed via bore 90 p provided in its front wall 90 t.Front wall 90 t may be advantageously formed in a conical shape having aflare 90 f at its tip for assisting in mounting it in the wall of heart10. Said mounting of ventricular function assisting device 90 ispreferably carried out by forming a small incision 10 a in the wall ofthe heart and introducing the flaring front end 90 f of device 90thereinto such that the opening 90 a of bore 90 p communicates with aninterior of a heart chamber. Device 90 may be secured in its mountedstate to the heart 10 by means of pressure, tightening or suturing.Volumes of blood may thus be injected/discharged into/from device 90.

With reference to FIG. 9B, ventricular function assisting device 90further comprises an electromagnetic plunger 93, and a first coil 91 a,winded over (or inside) a rear section of cylindrical body of device 90,and a second coil 91 b wound over (or inside) a front section of device90 near its front wall 90 t, said coils are adapted to receiveelectrical currents and apply opposing magnetic fields generallyperpendicular to the plane of magnetic plunger 93, such that saidelectromagnets may be activated alternately to apply back and forthdriving forces over magnetic plunger 93.

More particularly, during the diastole second coil 91 b is activated toapply axial forces over plunger 93 for sliding it towards the rear sideof device 90 (i.e., by applying magnetic repulsion forces) and therebypump a volume of blood (e.g., about 10-200 ml) thereinto and assist inreducing the pressure in heart 10 and in pumping blood into it. Therearward movement of plunger 93 may be limited by a stopper 90 s formedin, or attached on, a rear section of the internal wall of device 90.During the systole, the first coil 91 a is activated to apply axialforces over plunger 93 for sliding it towards the front side of device90 (i.e., by applying magnetic attraction forces) and thereby dischargea volume of blood therefrom and assist in increasing the pressure inheart 10 and in pumping blood therefrom.

Ventricular function assisting device 90 may be manufactured from a typeof biocompatible metalic material, for example stainless steel, oralternatively from a type of biocompatible polimer, preferably fromstainless steel, its diameter may generally be in the range of 10 to 60mm, preferably about 25 mm, and its length may generally be in the rangeof 10 to 40 mm, preferably about 30 mm. The volume of device 90 maygenerally be in the range of 10 to 2.00 ml, preferably about 50 ml.Coils 91 are preferably made from an electrically conducting wire madefrom copper the diameter of the wires and the number of turns arepreferably adjusted for generating a magnetic filed in the range of0.000001 to 0.1 Tesla responsive to electrical currents in the range of0.0001 to 10 amperes.

The electrical current may be supplied to coils 91 by an implantablebattery (not shown). The operation of coils 91 may be activated by animplantable control logic and/or programmable controller (not shown),employing ECG sensing means (or pacemaker) for synchronizing deviceoperation with the heart function.

Magnetic plunger 93 is a permanent magnet made from a type of magneticmaterial, such as for example stainless steel, its thickness maygenerally be in range of 0.5 to 3 mm, and its diameter is adjusted toallow it to smoothly slide inside device 90 along its length. Themagnetic strength of magnetic plunger 93 may generally be in the rangeof 0.001 to 1000 gauss.

Ventricular function assisting device 90 may be connected to the heartin a minimal invasive procedure via a small opening formed in thepatient's chest. The device may be connected to the tissue of the leftventricle by suturing, insertion under pressure and/or threading it intothe tissue.

Device 12 may be installed on the wall of the heart of a patient in aprocedure comprising the following steps: open chest surgery,thoracotomy, or minimal invasive thoracoscopy. Apertures 10 a and 10 bmay be formed in the wall of heart 10 by a surgical cutting device or bya needle, and device 12 may be attached to the wall of the heart 10 bypressure, surgical sutures, stapling devices or adhesives.

FIGS. 10A and 10B schematically illustrate a method and a device 95 fordelivering treatment device 100 into the heart and for mounting the sameon its inner wall. Treatment device 100 is configured for implantationinside a ventricle of a living heart 10, which includes fixationelements 98 a and 98 b configured to be pressed onto opposing wallsregions in the ventricle by an elastic (spring-like) energy absorbingelement (100). Fixation elements 98 a and 98 b (also referred to hereinas expandable elements) are connected in both sides of the elasticelements which is designed to be inserted into the ventricle in apreloaded state. After implantation in the ventricle of heart 10 energyfrom the ventricular movement of the heart is absorbed in the elasticelement, such that additional energy is absorbed by it during thesystolic phase of the heart, which energy is then released to theventricle through the fixation elements 98 a and 98 b during thediastolic phase, thereby assisting in improving diastolic functioning ofthe heart.

Delivery tool 95 generally comprises a tube 97 and a guide wire 99passing there inside. At the first step of an insertion procedure theguide wire 99 is inserted at the desired location to mark the deviceimplantation trajectory. The device 100 can be placed at differentlocations, e.g., between the lateral wall to the septum, or between theanterior to the posterior walls. Tube 97 is introduced into heart 10over guide wire 99 via a small incision 101 formed in the free wall 10 wof the heart 10, such that opening 97 a of tube 97 is placed more orless in front of the distal wall 10 d.

In this state a device 100 (e.g., bent spring) may be installed insideheart 10. The device to be installed is advanced through tube 97 and itmay be installed by performing the following steps: advancing a portionof device 100 such that a first expandable element 98 a of device 100 isreleased through opening 97 a, the state of said first expandableelement 98 a is then changed into an open (deployed) state and pressedagainst the distal wall 10 d of heart 10 by distal anchoring means 98 c(e.g., bars, screw, hook); retracting tube proximally such that a secondexpandable element 98 b is released via opening 97 a, said secondexpandable element 98 b is then changed into its deployed state andpressed against the proximal wall 10 w of heart 10 by wall anchoringmeans 98 d (e.g., bars, screw, hook) as tube 97 is withdrawn from heart10 via incision 101.

Tube 97 may be manufactured from Nylon, Silicon, Teflon, or any kind ofsuitable polymer, preferably from Teflon, and its diameter may generallybe about 2 to 10 mm.

Device 100 may be used for applying forces over heart walls 10 w and 10d by means of, but not limited to: buckling bar, torsion spring (notshown), or pressing spring (not shown).

Wall anchoring 98 d and/or distal anchoring 98 c may be used aselectrical connecting means for delivering electrical signals producedby pacemaker 85. When pacemaker 85 is attached to the wall anchoring 98d and distal anchoring 98 c that is implanted in the heart tissue andused to conduct the electric signal from pacemaker 85 via electricalcables 85 w to heart tissue and to pace the left ventricle, or the rightventricle, or both of them.

Expandable elements 98 a and 98 b may be manufactured from an elasticmaterial, preferably from nitinol, and it may be formed in a shape of aflower which leaves (e.g., having 3 to leaves each having a length ofabout 3 to 20 mm) are configured to allow it to be packed compactly suchthat it may be delivered through tube 97 and open laterally when it isreleased therefrom. Expandable elements 98 a and 98 b may bemanufactured form a thin and elastic wire having a diameter of about 0.1to 2 mm.

Distal anchoring 98 c and wall anchoring 98 d may be manufactured fromnitinol or Conichrome (fwm 1058), for example, in shape of short tubeshaving a length of about 3 to 20 mm and inner diameter of about 1 to 10mm. Distal anchoring 98 c and wall anchoring 98 d are preferablyconnected to the centers of expandable elements 98 a and 98 b andperpendicular to their plains when in their deployed state, to allowthem to be delivered over guide wire 99. Distal anchoring 98 c and wallanchoring 98 d are configured to be introduced into the wall of theheart for attaching treatment device 100. This is preferably achieved byscrewing or sticking.

Pacemaker 85 can be implant together with device 100, or later ifrequired, through tube 97. Pacemaker 85 is implanted in the patient'sbody in substantially the same way as in conventional pacemakerprocedures, such that it may be placed under the chest or abdomen skinof the patient, but instead of using the conventional pacemakerelectrodes the electrical signals it produces are delivered to thepatient's heart through anchoring means the wall anchoring 98 c and/orthe distal anchoring 98 d.

All of the above mentioned parameters are given by way of example only,and may be changed in accordance with the differing requirements of thevarious embodiments of the present invention. Thus, the abovementionedparameters should not be construed as limiting the scope of the presentinvention in any way. In addition, it is to be appreciated that thedifferent plungers, tubes, springs, and other members, describedhereinabove may be constructed in different shapes (e.g. having oval,square etc. form in plan view) and sizes differing from thoseexemplified in the preceding description.

The above examples and description have of course been provided only forthe purpose of illustration, and are not intended to limit the inventionin any way. As will be appreciated by the skilled person, the inventioncan be carried out in a great variety of ways, employing more than onetechnique from those described above, all without exceeding the scope ofthe invention.

1.-27. (canceled)
 28. A treatment device for implantation inside aventricle of a living heart and for applying forces over its walls, saidtreatment device comprising two expandable elements fixedly attached toa bent spring, and anchoring means attached to each of said expandableelements, wherein said treatment device is capable of being placedinside a tube for delivery and placement in said living heart ventricleby introducing said tube into said heart ventricle and discharging saiddevice thereinside such that its expandable elements change into adeployed state as their anchoring means are attached to the wall of theheart ventricle.
 29. A device according to claim 28 further comprising apacemaker electrically coupled to it for delivering electrical signalsto the tissue of the heart.
 30. A device according to claim 28 whereinthe treatment device expandable elements are expandable fixationelements.
 31. A device according to claim 28 wherein the treatmentdevice is adapted to store energy from the ventricular motion of theheart during the systolic phase and release stored energy during thediastolic phase, thereby assisting in improving diastolic functioning ofthe heart.
 32. A device according to claim 28 wherein said device isimplantable in a preload state.
 33. A method for delivering a treatmentdevice according to claim 28 into a ventricle of a living heartcomprising: introducing a guidewire into said heart ventricle via asmall incision; introducing the tube comprising said treatment deviceinto said heart ventricle over said guidewire; distally advancing aportion of said device such that a first expandable element is releasedand changed into a deployed state, pressed against the wall said heartventricle and attached thereto by its anchoring means; retracting saidtube proximally such that a second expandable element is released andchanged into a deployed state, pressed against the wall of said heartventricle and become attached thereto by its anchoring means; andwithdrawing said tube from said heart ventricle via said incision.